Archives of Acoustics

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Description

Archives of Acoustics is an English-language peer-reviewed quarterly
journal publishing original research papers from all areas of acoustics
and abstracts from some specialised acoustical conferences. It gives
free internet access to its full content (abstracts of research papers)
to current issues.

Archives of Acoustics, the peer-reviewed quarterly journal publishes
original research papers from all areas of acoustics like:

Abstract

Ultrasonic emulsifying processes of immiscible liquids can be used to
obtain stable emulsions. The authors used an ultrasonic sandwich head with
an energy concentrator to obtain a suitable value of the energy density
necessary for the emerge of ultrasonic cavitation. Two piezoelectric ring
(Dext = 50 mm) transducers of Pz-26 type produced by FERROPERM were used
to design the ultrasonic sandwich head. The frequency of the ultrasonic
wave was 18.4 kHz and the excitation time of the ultrasonic transducer
exiting 5 minutes. Visible bubbles during the generation of ultrasonic
waves appeared in the mixture after exceeding the cavitation threshold.
The authors determined also the cavitation threshold by measuring the
electrical voltage conducted to the transducers. To receive long-lasting
emulsion, the electrical voltage attained 300 Vpeak. The dispersion
dependence on the emulsifying time was determined. The emulsion of linseed
oil and water was stable through some months without surfactants.

Abstract

The purpose of this work is to distinguish between Acoustic Emission (AE)
signals coming from mechanical friction and AE signals coming from
concrete cracking, recorded during fourteen seismic simulations conducted
with the shaking table of the University of Granada on a reinforced
concrete slab supported on four steel columns. To this end, a particular
criterion is established based on the Root Mean Square of the AE waveforms
calculated in two different temporal windows. This criterion includes a
parameter calculated by optimizing the correlation between the mechanical
energy dissipated by the specimen (calculated by means of measurements
with accelerometers and displacement transducers) and the energy obtained
from the AE signals recorded by low-frequency piezoelectric sensors
located on the specimen. The final goal of this project, initiated four
years ago, is to provide a reliable evaluation of the level of damage of
Reinforced Concrete specimens by means of AE signals to be used in future
Structural Health Monitoring strategies involving RC structures.

Abstract

Phantom sources are known to be perceived similar to real sound sources
but with some differences. One of the differences is an increase of the
perceived source width. This article discusses the perception,
measurement, and modeling of source width for frontal phantom sources with
different symmetrical arrangements of up to three active loudspeakers. The
perceived source width is evaluated on the basis of a listening test. The
test results are compared to technical measures that are applied in room
acoustics: the inter-aural cross correlation coefficient (IACC) and the
lateral energy fraction (LF). Adaptation of the latter measure makes it
possible to predict the results by considering simultaneous sound
incidence. Finally, a simple model is presented for the prediction of the
perceived source width that does not require acoustic measurements as it
is solely based on the loudspeaker directions and gains.

Abstract

The paper presents an analysis of the results of ultrasound transmission
tomography (UTT) imaging of the internal structure of a breast
elastography phantom used for biopsy training, and compares them with the
results of CT, MRI and, conventional US imaging; the results of the
phantom examination were the basis for the analysis of UTT method
resolution. The obtained UTT, CT and MRI images of the CIRS Model 059
breast phantom structure show comparable (in the context of size and
location) heterogeneities inside it. The UTT image of distribution of the
ultrasound velocity clearly demonstrates continuous changes of density.
The UTT image of derivative of attenuation coefficient in relation to
frequency is better for visualising sharp edges, and the UTT image of the
distribution of attenuation coefficient visualises continuous and stepped
changes in an indirect way. The inclusions visualized by CT have sharply
delineated edges but are hardly distinguishable from the phantom gel
background even with increased image contrast. MRI images of the studied
phantom relatively clearly show inclusions in the structure.
Ultrasonography images do not show any diversification of the structure of
the phantom. The obtained examination results indicate that, if the
scanning process is accelerated, ultrasound transmission tomography method
can be successfully used to detect and diagnose early breast malignant
lesions. Ultrasonic transmission tomography imaging can be applied in
medicine for diagnostic examination of women’s breasts and similarly for
X-ray computed tomography, while eliminating the need to expose patients
to the harmful ionising radiation.

Abstract

The scattering of plane steady-state sound waves from a viscous
fluid-filled thin cylindrical shell weak- ened by a long linear slit and
submerged in an ideal fluid is studied. For the description of vibrations
of elastic objects the Kirchhoff-Love shell-theory approximation is used.
An exact solution of this problem is obtained in the form of series with
cylindrical harmonics. The numerical analysis is carried out for a steel
shell filled with oil and immersed in seawater. The modules and phases of
the scattering amplitudes versus the dimensionless wavenumber of the
incident sound wave as well as directivity patterns of the scattered field
are investigated taking into consideration the orientation of the slit on
the elastic shell surface. The plots obtained show a considerable
influence of the slit and viscous fluid filler on the diffraction process.

Abstract

Study of the sea noise has been a subject of interest for many years. The
first works in this scope were published at the turn of the twentieth
century by Knudsen (Knudsen et al., 1948) and G. Wenz (Wenz, 1962).
Disturbances called “shipping noise” are one of the important components
of the sea noise.
In this work the results of an experimental research of underwater noise
produced by a small ship of a classic propulsion are presented. A linear
receiving antenna composed of two orthogonal components was used in the
investigation. Identification of the main sources of acoustic waves
related with the ship was achieved. In addition, the intensity of the wave
was measured. The research was performed in conditions of the shallow sea.

Abstract

Weakly nonlinear sound propagation in a gas where molecular vibrational
relaxation takes place is studied. New equations which govern the sound in
media where the irreversible relaxation may take place are derived and
discussed. Their form depends on the regime of excitation of oscillatory
degrees of freedom, equilibrium (reversible) or non-equilibrium
(irreversible), and on the comparative frequency of the sound in relation
to the inverse time of relaxation. Additional nonlinear terms increase
standard nonlinearity of the high-frequency sound in the equilibrium
regime of vibrational excitation and decrease otherwise. As for the
nonlinearity of the low-frequency sound, the conclusions are opposite.
Appearance of a non-oscillating additional part which is a linear function
of the distance from the transducer is an unusual property of nonlinear
distortions of harmonic at the transducer high-frequency sound

Abstract

The paper analyzes the estimation of the fundamental frequency from the
real speech signal which is obtained by recording the speaker in the real
acoustic environment modeled by the MP3 method. The estimation was
performed by the Picking-Peaks algorithm with implemented parametric cubic
convolution (PCC) interpolation. The efficiency of PCC was tested for
Catmull-Rom, Greville, and Greville two- parametric kernel. Depending on
MSE, a window that gives optimal results was chosen.

Abstract

The present study consisted of two experiments. The goal of the first
experiment was to establish the just noticeable differences for the
fundamental frequency of the vowel /u/ by using the 2AFC method. We
obtained the threshold value for 27 cents. This value is larger than the
motor reaction values which had been observed in previous experiments
(e.g. 9 or 19 cents). The second experiment was intended to provide
neurophysiological confirmation of the detection of shifts in a frequency,
using event-related potentials (ERPs). We concentrated on the mismatch
negativity (MMN) - the component elicited by the change in the pattern of
stimuli. Its occurrence is correlated with the discrimination threshold.
In our study, MMN was observed for changes greater than 27 cents - shifts
of ±50 and 100 cents (effect size - Cohen’s d = 2.259). MMN did not appear
for changes of ±10 and 20 cents. The results showed that the values for
which motor responses can be observed are indeed lower than those for
perceptual thresholds.

Abstract

The paper presents results of hearing loss measurements provided for 81
young people (from 16 to 25 years old). The main aim of the work was to
find the influence of headphones of the types used (closed, semi-open,
open and in-ear) on the hearing losses. The first part of the research was
to answer questions about the influence of: time of listening, loudness of
music, other noise exposures as well as the type of the headphones used.
It turned out that all factors mentioned above influence thresholds of
hearing but the found dependencies are not explicit. The greatest hearing
losses were observed for people who work as sound reinforcement engineers
and, moreover, no influence of the headphone types was found for them. It
turned out that the use of in-ear headphones causes the greatest hearing
losses for some subjects (thresholds shifted up to about 20 dB HL at 4
kHz). The daily time of a listening also affected the hearing thresholds.
It was found that for users of in-ear and close headphones, an average
time of musical exposure of three hours causes the hearing loss of 10-15
dB HL at higher frequencies. The use of open as well as semi-open
headphones has no influence on the hearing damage. Thus it would be stated
that these kinds are safety in use. Almost 15% of the investigated young
people have their thresholds shifted up at higher frequencies,
particularly at 4 kHz, which means that they have the first symptoms of a
permanent hearing damage.

Abstract

Noise measurements have been carried out at eleven different sites located
in three prominent cities of the Tarai region of India to evaluate the
effectiveness of vegetation belts in reducing traffic noise along the
roadsides. Attenuation per doubling of distance has been computed for each
site and excess attenuation at different 1/3 octave frequencies has been
estimated. The average excess attenuation is found to be approximately 15
dB over the low frequencies (200 Hz to 500 Hz) and between 15 dB to 20 dB
over the high frequencies (8 kHz to 12.5 kHz). Over the critical middle
frequencies (1-4 kHz), the average excess attenuation (between 10-15 dB)
though not as high, is still significant, with a number of sites showing
an excess attenuation of 15 dB or more at 1 kHz. The results indicate that
sufficiently dense vegetation belts along the roadsides may prove as
effective noise barriers and significant attenuation may be achieved over
the critical middle frequencies (1-4 kHz).

Abstract

Previous studies concerning the categorisation method have been based on
short daytime measure- ments. These studies demonstrated urban-noise
stratification in the daytime. Nevertheless, legislation and standards
refer to noise estimation throughout the day. This paper presents the
first attempt to apply the categorisation method to indicators obtained
through long-term measurements. The study was conducted in Plasencia,
Extremadura (Spain) which has approximately 41,500 inhabitants. First, we
conducted a stratification of the roads using the categorisation method.
Second, long-term measurements (approxi- mately one week) were conducted
at different sampling locations across different categories of streets.
The results were analysed by category. Moreover, the profile of the
noise-level variation was analysed during the day. The results revealed a
stratification of sound levels measured across the different categories.
Furthermore, we found health risks due to the noise levels in this town.
Short-term measurements were also conducted to complete the categorisation
method suitability analysis.

Abstract

The noise of motor vehicles is one of the most important problems as
regards to pollution on main roads. However, this unpleasant
characteristic could be used to determine vehicle speed by external
observers. Building on this idea, the present study investigates the
capabilities of a microphone array system to identify the position and
velocity of a vehicle travelling on a previously established route. Such
linear microphone array has been formed by a reduced number of microphones
working at medium frequencies as compared to industrial microphone arrays
built for location purposes, and operates with a processing algorithm that
ultimately identifies the noise source location and reduces the error in
velocity estimation

Abstract

This paper presents an investigation about acoustic absorption of mortars
with partial replacement of sand by waste (plywood formwork, rice husk,
and thermoplastic shoe counters), examining different levels of
replacement (0%, 5%, 10%, 25%, and 50%). The measurement of acoustic
absorption was performed using a plane wave impedance tube with 100 mm
diameter, using mortar samples of 20 mm, in frequency range 200-2000 Hz.
Results demonstrated that some composite with waste presented noise
reduction coefficient (NRC) above the reference mortar (NRC = 0.0343),
such as a composite with 50% rice husk (NRC = 0.2757) and other with 50%
of plywood waste (NRC = 0.2052). Since there is virtually no cost or
difficulty to use these residuals, it may be concluded that it is a
sustainable alternative to improve the acoustic comfort and reduce the
impact of the waste on the environment.

Abstract

The sompoton is one of famous traditional musical instruments in Sabah.
This instrument consists of several parts with the vibrator being the most
important one. In this paper, the vibrator is modeled as a clamped bar
with a uniformly distributed mass. By means of this model, the fundamental
frequency is analyzed with the use of an equivalent single degree of
freedom system (SDOF) and exact analysis. The vibrator is made of aluminum
in different sizes and is excited using a constant air jet to obtain its
fundamental resonance frequency. The fundamental frequency obtained from
the experimental measurement is compared with the theoretical values
calculated based on the equivalent SDOF and exact analysis theories. It is
found that the exact analysis gives a closer value to the experimental
results as compared to the SDOF system. Although both the experimental and
theoretical results exhibit the same trend, they are different in
magnitude. To overcome the differences in both theories, a correction
factor is added to account for the production errors.

Instructions for authors

Author Guidelines• Manuscripts intended for publication in Archives of Acoustics should be submitted in pdf format by an on-line procedure.• Manuscript should be original, and should not be submitted either previously or simultaneously elsewhere, neither in whole, nor in part.• Submitted papers must be written in good English and proofread by a native speaker.• Basically, the papers should not exceed 40 000 typographic signs.• Postal addresses, affiliations and email addresses for each author are required.• Detailed information see Article Requirements.• Manuscript should be accompanied by a cover letter containing the information: o why the paper is submitted to ARCHIVES OF ACOUSTICS,o suggestion on the field of acoustics related to the topic of the submitted paper,o the statement that the manuscript is original, the submission has not been previously published, nor was sent to another journal for consideration,o 3–5 names of suggested reviewers together with their affiliations, full postal and e-mail addresses; at least 3 suggested reviewers should be affiliated with other scientific institutions than the affiliations of the authors,o author’s suggestion to classification of the paper as the research paper, review paper or technical note.Article Requirements1. At submission time only a PDF file is required. After acceptance, authors must submit all source material (see information about Figures). Authors can use their preferred manuscript-preparation software. The journal itself is produced in LaTeX, so accepted articles will be converted to LaTeX at production time.2. The title of the paper should be as short as possible. 3. Full names and surnames should be given.4. The full postal address of each affiliation, including the country name should be provided. Affiliations should contain the full postal address, as well as an e-mail address of one author designated as corresponding author.5. The text should be preceded by a concise abstract (less than 200 words).6. Keywords should be given. 7. The formulae to be numbered are those referred to in the paper, as well as the final formulae. 8. All notations should be written very distinctly.9. References in the text (author(s) and year of publication) are to be cited between parentheses. Items appearing in the reference list should be complete, including surname and the initials of the first name of the author, the full title of the paper/book in English followed by the information on the original paper language. In case of a book, the publisher's name, the place and year of publication should be given. In case of a periodical, the full title of the periodical, consecutive volume number, current issue number, pages, and year of publication should be given. All references in the bibliography should be cited in the text, and arranged in alphabetical order by authors' last name. For more information on references see http://acoustics.ippt.gov.pl/public/Instructions.pdf.10. Figures must be of publication quality. Each figure should be saved in separate file and captioned and numbered so that it can float. After acceptance, Authors will need to submit the original source files for all photos, diagrams and graphs in manuscript.For diagrams and graphs vector EPS or vector PDF files are the most useful. Make sure that what you're saving is vector graphics and not a bitmap. Please also include the original data for any plots. This is particularly important if you are unable to save Excel-generated plots in vector format. Saving them as bitmaps is not useful; please send the Excel (.xls) spreadsheets instead.Photographs should be high-quality – with resolution no lower than 300 dpi.Pack all figure files into a single archive (zip, tar, rar or other format) and then upload on the magazine web site.

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